Bicycle hub with an attached cooling disk

ABSTRACT

A bicycle hub brake component is provided for braking a hub of a wheel mounted on a bicycle frame The component comprises a brake drum and a cooling disk. The brake drum has a drum body that is adapted to rotate integrally with the hub, wherein the drum body has a brake face on an inner peripheral surface thereof. The cooling disk is crimped and/or caulked to an outer peripheral surface of the brake drum.

BACKGROUND OF INVENTION

The present invention is directed to bicycle brake devices and, moreparticularly, to bicycle brake devices that are used to brake a hub of abicycle wheel.

Bicycle braking devices currently available include rim braking devicesand hub braking devices. Rim braking devices include cantilever brakesor caliper brakes that brake the rim of the wheel. Hub braking devicesbrake the wheel hub, and they include drum brakes, band brakes, rollerbrakes and the like.

A hub brake brakes the hub of the wheel, so it is able to providebraking even if the wheel rim is warped. Drum brakes and roller brakes,which are hub braking devices of this kind, effect braking by means offriction created when the inside peripheral face of a tubular brake drumthat rotates in unison with the wheel hub is contacted by a brake shoe.In a roller brake, rollers spaced apart in the circumferential directionare displaced diametrically outwardly by a cam to move the brake shoe.Grease usually is injected into the interior of a roller brake to ensuresmooth displacement of the rollers.

In some brake devices of this kind, a brake drum may be formed from astainless steel alloy with a brake face on its inner peripheral surface.The brake drum may be provided with a cooling disk having fins that maybe fabricated of aluminum alloy. Such a cooling disk has a high heattransfer capability to dissipate the heat generated by contact betweenthe brake shoe and the brake face of the brake drum. As a result,thermally induced deterioration in braking performance can be held incheck.

One possible approach to fastening the cooling disk to the brake druminvolves inserting the brake drum in a mold and insert molding to formthe cooling disk. However, when the cooling disk is fastened to thebrake drum by an integral molding process, there is a risk of problemssuch as discoloration or deformation of the brake drum due to the heatof molding, since the brake drum is fabricated of metal. Parts that havebeen subjected to metal plating are particularly susceptible todiscoloration during insert molding. Discoloration and deformationrequire manual touchup in a subsequent process, thus resulting in a morecomplicated production process and higher production costs. Integralmolding also requires the transportation of the brake drums to separatelocations where casting equipment is located. The brake drums then mustbe properly positioned in the mold. This creates a laborious andcomplicated production process as well as the need for complicated andexpensive forming molds, thus further increasing production costs.

SUMMARY OF THE INVENTION

The present invention is directed to inventive features of a bicyclebraking device. In one embodiment, a bicycle hub brake component isprovided for braking a hub of a wheel mounted on a bicycle frame Thecomponent comprises a brake drum and a cooling disk. The brake drum hasa drum body that is adapted to rotate integrally with the hub, whereinthe drum body has a brake face on an inner peripheral surface thereof.The cooling disk is crimped and/or caulked to an outer peripheralsurface of the brake drum. Additional inventive features will becomeapparent from the description below, and such features alone or incombination with the above features may form the basis of furtherinventions as recited in the claims and their equivalents.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side view of a particular embodiment of a bicycle thatincludes braking components described herein;

FIG. 2 is a schematic illustration of a particular embodiment of a brakesystem for the bicycle;

FIG. 3 is a side view of a particular embodiment of a front brakedevice;

FIG. 4 is a front view of the front brake device;

FIG. 5 is a side view of the front brake device with the cover removed;

FIG. 6 is an enlarged partial cross-sectional view of the front brakedevice;

FIG. 7(A) is a partial cross-sectional view of a particular embodimentof a cooling disk press fit to a brake drum;

FIG. 7(B) is a partial cross-sectional view of the cooling disk crimpedand caulked to the brake drum;

FIG. 8 is an exploded view of a particular embodiment of the bicyclebrake device;

FIG. 9 is a perspective view of a particular embodiment of a retainingmember;

FIG. 10 is a cross sectional view of the retaining member of FIG. 9 in acrimped condition;

FIG. 11 is a perspective view of another embodiment of a retainingmember;

FIG. 12 is a cross sectional view of the retaining member of FIG. 11 ina crimped condition;

FIG. 13 is a perspective view of particular embodiments of an insertmember and a detaining portion of a bracket body;

FIG. 14 is a side cross sectional view of the insert member and thebracket body prior to mounting the insert member;

FIG. 15 is a side cross sectional view of the insert member and thebracket body after mounting the insert member;

FIG. 16 is a side view of a particular embodiment of a brake shoeassembly;

FIG. 17 is a plan view of a portion of the brake shoe assembly;

FIG. 18 is an enlarged view of a distal end of a brake shoe;

FIG. 19 is an exploded view of a particular embodiment of mountingportions of the actuating arm;

FIG. 20 is a partial cross sectional view of the brake device in a brakereleased state;

FIG. 21 is a partial cross sectional view of the brake device in a brakeactivated state; and

FIG. 22 is a cross sectional view of another embodiment of a coolingdisk attached to a brake drum.

DETAILED DESCRIPTION

FIG. 1 is a side view of a particular embodiment of a bicycle thatincludes braking components described herein. In this embodiment, thebicycle comprises a frame 1 that has a frame body 2 and a front fork 3;a handlebar portion 4 comprising a handle stem 10 fastened to the top offront fork 3 and a handlebar 11 fastened to handle stem 10 for steering;a saddle 9 for sitting; a front wheel 6; a rear wheel 7; a brake system8 for braking front wheel 6 and rear wheel 7; and a drive section 5 fortransmitting rotation of pedals 5 a to rear wheel 7.

Front wheel 6 and rear wheel 7 have front and rear hubs 6 a (FIG. 4,wherein only the front hub 6 a is shown), each having a hub spindle 15 a(FIG. 6), front and rear rims 6 b, 7 b (FIG. 1) disposed at the outsideperiphery of hubs 6 b, tires 6 c, 7 c attached to front and rear rims 6b, 7 b, and spokes 6 d, 7 d connecting the hubs 6 a with the respectiverims 6 b, 7 b. As shown in FIG. 6, hub 6 a hub spindle 15 a isnonrotatably mounted on front fork 3 of frame 1, and a hub shell 15 b isrotatably supported on hub spindle 15 a. Front hub 6 a has a quickrelease lever 6 e (FIG. 1) to provide a quick release hub that is easyto detach. The quick release mechanism is known and described, forexample, in the 1993 Japanese Industrial Standard (JIS) Bicycle Edition,p. 276, published by Jitensha Sangyo Shinko Kyokai. Thus, a detaileddescription of the quick release mechanism will not be provided here. Inthis embodiment, the hubs6 a are fastened to the front fork 3 and chainstay 2 a with an ordinary hexagon cap nut 45.

As shown in FIG. 2, brake system 8 has front and rear brake levers 12 f,12 r, brake devices 13 f, 13 r actuated by front and rear brake levers12 f, 12 r, and front and rear brake cables 14 f, 14 r respectivelylinking the front and rear brake levers 12 f, 12 r with the front andrear brake devices 13 f, 13 r. Brake cables 14 f, 14 r have inner cables16 f, 16 r, the two ends of which are linked to front and rear brakelevers 12 f, 12 r and the front and rear brake devices 13 f, 13 r. Brakecables 14 f, 14 r also have outer cables 17 f, 17 r sheathing the innercables 16 f, 16 r. The front brake lever 12 f is mounted to the insideof a grip 18 a mounted on the left end of handlebar 11, and the rearbrake lever 12 r is mounted to the inside of a grip 18 b mounted on theright end of handlebar 11. Brake levers 12 f, 12 r are identicalcomponents disposed in a mirror image relationship. Each brake lever 12f, 12 r has a lever bracket 20 mounted on handlebar 11, a lever member21 pivotably supported on a pivot shaft 20 a on lever bracket 20, and anouter detaining portion 22 screwed onto lever bracket 20. Each leverbracket 20 has a mounting portion 20 b and a female threaded portion 20c, wherein mounting portion 20 b is detachably mountable to handlebar11, and outer detaining portion 22 is threaded into female threadedportion 20 c. Inner cables 16 f, 16 r passes through their respectiveouter detaining portions 22 and are detained by corresponding innerdetaining portions 21 a mounted to each lever member 21. Lever member 21is biased towards the brake release position by a biasing member (notshown).

In this embodiment, the front and rear brake devices 13 f, 13 r areroller brake devices. Brake devices 13 f, 13 r function to brake the hub6 a of front wheel 6 and rear wheel 7, respectively. As shown in FIGS.2, 3, and 8, brake devices 13 f, 13 r have fastening brackets 30 f, 30 rfor nonrotatably fastening brake devices 13 f, 13 r to the front fork 3or chain stay 2 a of the bicycle; brake bodies 32 f, 32 r; and brakeactuating portions 33 f, 33 r for actuating the brake bodies 32 f, 32 r.Each fastening bracket 30 f, 30 r has a bracket body 34 with a firstface and a second face produced, for example, by press forming a sheetof steel, and a cover member 35 securely fitting onto bracket body 34for covering the second face of bracket body 34. Cover member 35 isformed by press forming a thin metal sheet, has a baked-on finish on itssurface, and has indicia such as a model number imprinted thereon.Bracket body 34 has a basal portion 34 a (FIG. 8) through which hubspindle 15 is passed, a tapering arm portion 34 b that extendssubstantially diametrically from basal portion 34 a, and a detainingportion 34 c formed at the distal end of arm portion 34 b with asubstantially equal width plate configuration. As shown in FIG. 6, thebasal portion 34 a of bracket body 34 is fastened to hub spindle 15 a bymeans of the hexagonal cap nut 45 screwed onto one end of hub spindle 15a. On basal portion 34 a, except in the arm portion 34 b, is formed atubular portion 34 d of very short length. This tubular portion 34 dforms a member mounting portion 38 comprising a pair of mounting holes38 a, 38 b for mounting first detaining members 36, 37 that prevent thebrake drum 40 from coming off in a manner described below.

As shown in FIGS. 1 and 13–15, the detaining portion 34 c of bracketbody 34 is fastened to a bracket fastening member 25 f, 25 r. Thedetaining portion 34 c of the front bracket body 34 is detaineddetachably, by a one-touch operation, by bracket fastening member 25 fin order to facilitate replacement of front wheel 6. On a first face ofthe front detaining portion 34 c (the left face in FIG. 14), there isformed a recess 34 e recessed inwardly and extending in the mountingdirection. Recess 34 e is produced by a press forming process, forexample, and projects towards a second face of front detaining portion34 c (the right face in FIG. 14). Bracket fastening member 25 f issupplied together with the front brake device 13 f by the brakemanufacturer, and it is welded to the front fork 3 of the bicycle frame1. Bracket fastening member 25 f has a detaining space 25 a fordetaining detaining portion 34 c when the latter is inserted therein.The two side walls 25 b of detaining space 25 a are bowed slightlyinward so that detaining space 25 a has greater width at its mouth (thedistance between the side walls 25 b at the lower end in FIG. 15) forinsertion of detaining portion 34 c than it does in its medial portionsituated further inward. Since the width at the mouth is greater thanthe width further inward, detaining portion 34 c can be detainedregardless of differences in configuration of the front fork 3 of thebicycle.

An insert member 19 produced, for example, by bending a thin sheet ofstainless steel for ease of manufacture, durability and corrosionresistance, is mounted on the front detaining portion 34 c. Insertmember 19 is arranged such that it is situated within detaining space 25a when mounted on detaining portion 34 c. Insert member 19 has first andsecond contact portions 19 a, 19 b and a third contact portion 19 c.First and second contact portions 19 a, 19 b mount onto the detainingportion 34 c from the distal edge thereof, and third contact portion 19c contacts a side of detaining portion 34 c due to being bent out fromthe first contact portion 19 a which is juxtaposed to a first face ofdetaining portion 34 c. The first and second contact portions 19 a, 19 bare bent towards the two faces of detaining portion 34 c so that thebent portions are situated at the distal edge thereof. A convex portion19 d is formed on first contact portion 19 a for mating with recessedportion 34 e of detaining portion 34 c. By engaging convex portion 19 dwithin recessed portion 34 e, insert member 19 may be mounted at adesired location on detaining portion 34 c when insert member 19 ismounted in fastening member 25 f. Since the second face of detainingportion 34 c projects outwardly (to the right in FIG. 14), the secondcontact portion 19 b of insert member 19 situated at this second face isbent diagonally. It is therefore easier to fill the gap of the detainingspace 25 a of bracket fastening member 25 f for reducing the chatter ofthe brake device 13 f in the axial direction when mounted on the frontfork 3. Furthermore, third contact portion 19 c is bent diagonally alongdetaining space 25 a as shown in FIG. 15. Accordingly, it is easy tofill in the convex gap of the detaining space 25 a of bracket fasteningmember 25 f for reducing chatter in the hub rotation direction.

As shown in FIGS. 2 and 3, bracket fastening members 25 f, 25 r andfastening brackets 30 f, 30 r, respectively, have mounted thereon outermounting portions 31 f, 31 r for detaining the outer cables 17 f, 17 r.For example, outer mounting portion 31 f may be screwed to the frontbracket fastening member 25 f. Outer mounting portion 31 f has an outerdetaining portion 31 a and an outer fastening portion 31 b. Outerdetaining portion 31 a is provided for detaining outer cable 17 f, andouter fastening portion 31 b is provided for fastening outer detainingportion 31 a in such a way that the detaining position of outerdetaining portion 31 a in the cable axis direction is adjustable bymeans of a screw. Brake play (i.e. the gap between the brake drum andthe brake shoe) can be adjusted by adjusting this axial position. Sinceouter mounting portions 31 f are mounted to the frame, there is no needto attach or detach the outer cable when attaching or detaching thewheel.

Since brake bodies 32 f, 32 r are of substantially identical structure,only the front brake body 32 f will be described. As shown in FIG. 6,front brake body 32 f has a brake drum 40 and a brake shoe 41. Brakedrum 40 has a cylindrical drum body 43 that rotates integrally with thehub shell 15 b through a left pocket 15 c. Drum body 43 is a stainlesssteel alloy member having a bowl configuration with a bottom portion 50and a peripheral portion 51 formed at the outside periphery of bottomportion 50. A contoured (splined) portion 50 b is formed on the insideperipheral surface of an opening 50 a in bottom portion 50, wherein thesplined portion 50 b meshes with a complementary splined portion formedon the outer peripheral surface of left pocket 15 c. As a result, drumbody 43 is nonrotatably mounted relative to hub shell 15 b.

A circular brake face 51 a is formed on the inside peripheral face ofperipheral portion 51, wherein brake shoe 41 is capable of contactingwith and releasing from brake face 51 a to provide a braking force tobrake drum 40. Brake face 51 a is produced by recessing the axial centerportion of peripheral portion 51 in an isosceles trapezoidal shape whosecross section constricts in width going outwardly in the diametricaldirection. As shown in FIGS. 7(A) and 7(B), the angle Î± at which thetwo sides of brake face 51 a intersect ranges from 15 Â° to 150 Â°,preferably 80 Â° to 100 Â°. Brake face 51 a has a diametricallyoutwardly extending annular grease filled recess 54 packed with grease.Grease filled recess 54 has a first groove 54 a, formed in the mostdeeply recessed portion of brake face 51 a so that grease tends to flowinto first groove 54 a through centrifugal force during riding, and apair of second grooves 54 b situated on brake face 51 a at oppositesides of first groove 54 a to increase the amount of grease that may besupplied. Grease filled recess 54 is packed with grease at the time ofassembly.

A cooling disk 44 made of aluminum alloy is thermally coupled to theouter peripheral surface of drum body 43. Cooling disk 44 has a tubularportion 44 b and a disk portion 44 c, wherein disk portion 44 c extendsdiametrically outward from tubular portion 44 b. A plurality of radiallyextending cooling fins 44 a (FIG. 4) are formed on the inside (rightside) face of cooling disk 44 for dissipating heat from hub body 43.Such dissipation is enhanced by the increased surface area as well asthe increased contact with air when the wheel is spinning.

As shown in FIGS. 7(A) and 7(B), a knurled portion 51 b is formed on theoutside peripheral face of peripheral portion 51 by means of a knurlingprocess in order to prevent rotation of cooling disk 44 relative to hubbody 43 when cooling disk 44 is mounted to hub body 43. The outerperipheral surface of peripheral portion 51 also has formed thereon afirst tapered face 51 c and a second tapered face 51 d situated onopposite sides of knurled portion 51 b, wherein tapered faces 51 c, 51 dtaper downwardly in the diametrical direction. First tapered face 51 cis provided for axially detaining the cooling disk 44 to drum body 43,and second tapered face 51 d is provided for fastening cooling disk 44to hub body 43 by crimping and/or caulking. A flat outer peripheralpress fitting face 51 e is formed between first tapered face 51 c andknurled portion 51 b. Cooling disk 44 is press fit onto the entirecircumference of press fitting face 51 e and the knurled portion 51 b sothat grease packed into the brake drum 40 can be prevented from flowingthrough the side of hub 6 a.

During the fabrication stage, a cylindrical caulk fastening portion 44 dis formed on a first end of tubular portion 44 b (the right end in FIG.7(A)). To fasten the cooling disk 44 to the drum body 43 during theassembly stage, the tubular portion 44 b is initially press fit onto theoutside peripheral face of drum body 43 as shown in FIG. 7(A). A shavingreservoir portion 58 is formed on the inside peripheral surface oftubular portion 44 b for holding shavings produced by knurled portion 51b during the press fitting process. Thereafter the caulk fasteningportion 44 d is bent diametrically inward towards the second taperedface 51 d of the drum body 43 as shown in FIG. 7(B) using a roller orsome other suitable jig. By press fitting the cooling disk 44 andcaulking it onto the drum body 43 in this manner, the cooling disk 44 issecurely fastened onto the drum body 43, especially in the axialdirection. The larger contact area produced by the tapered faces alsoimproves cooling efficiency. The press fitting/caulking operation doesnot require application of heat, and it can be performed at the samelocation. Thus, heat-induced discoloration and deformation is avoided,the labor entailed in the production process is reduced, and the coolingdisk 44 is fastened to the drum body 43 in a simple and inexpensivemanner.

The other end of the tubular portion 44 b of cooling disk 44 (the leftend in FIG. 7) has a diametrically outwardly projecting annular convexportion 44 e for preventing the brake drum 40 from coming off of thefastening bracket 30 when attaching or detaching the brake device 13 f.More specifically, two kinds of first retaining members 36, 37 (FIGS.8–12) are detachably mounted on member mounting portion 38 of tubularportion 34 d of bracket body 34, and a second retaining member 39 isproduced by bending cover member 35 diametrically inwardly. Firstretaining members 36, 37 and second retaining portion 39 are received inthe annular groove formed between annular convex portion 44 e and diskportion 44 c of cooling disk 44

As shown in FIGS. 9 and 10, first retaining member 36 is a bent platemember made of stainless steel alloy. First retaining member 36 has aretaining projection 36 a that is adapted to be fitted axially inwardlyof annular convex portion 44 e, a mounting portion 36 b produced bybending retaining projection 36 a so as to be situated against the innerperipheral face of tubular portion 34 d, and bent fastening portions 36c produced by cutting the two ends of mounting portion 36 b and bendingthem in the upward direction as shown in FIG. 9. These bent fasteningportions 36 c are inserted into mounting holes 38 a, 38 b from the innerperipheral side of tubular portion 34 d, and their distal ends are bentover to mount the first retaining member 36 onto the inside peripheralface of tubular portion 34 d as shown in FIG. 10.

As shown in FIGS. 11 and 12, first retaining member 37 is a bent platemember made of stainless steel alloy. First retaining member 37 hasretaining projection 37 a that is adapted to be fitted axially inwardlyof annular convex portion 44 e of cooling disk 44 a mounting portion 37b produced by bending retaining projection 37 a so as to be situatedagainst the outer peripheral face of tubular portion 34 d, and elasticfastening portions 37 c produced by cutting the two ends of mountingportion 37 b and bending them in the downward direction in a U-shape asshown in FIG. 11. These elastic fastening portions 37 c are insertedinto mounting holes 38 a, 38 b from the outside peripheral side oftubular portion 34 d. Once elastic fastening portions 37 c have passedthrough mounting holes 38 a, 38 b, they spread out due to elasticity andare elastically detained on tubular portion 34 d, thereby fastening thefirst retaining member 37 to the outside peripheral face of tubularportion 3. Although the tips of the elastic fastening portions 37 c areshown touching the inner peripheral surface of tubular portion 34 d,they may instead touch the side walls of mounting holes 38 a, 38 b. 4 d.First retaining member 37 may be removed by prying mounting portion 37b.

As shown in FIG. 8, the second retaining member 39 is formed by bendingthe cover member 35 inwardly. Second retaining member 39 also isprovided for preventing the brake drum 40 from coming off, as well as todetain the cover member 35 on the bracket body 34. Cover member 35 isfastened to tubular portion 34 d by means of elastic detention.Providing a second retaining member 39 on cover member 35 allows thenumber of retaining members 36,37 to be reduced as well as reducingmanufacturing costs and the number of steps required to attach thebrackete body 34 to brake drum 40. Cover member 35 has a bulging portion35 a formed so as to cover the outside peripheral side of firstretaining portion 37, thus making the first retaining member 37 (whichis easier to detach than the first retaining member 36 because the firstretaining member 36 was fastened to tubular portion 34 d by bending)harder to remove.

By preventing the brake drum 40 from coming off by means of firstretaining members 36, 37, which are detachable from the tubular portion34 d, and the second retaining member 39 formed on cover member 35,damage to fastening bracket 30 f and cover member 35 is prevented whenfirst retaining members 36,37 and second retaining member 39 areattached or detached. The brake drum 40 thus can be retained withoutbreaking fastening bracket 30 f or cover member 35, even when brakedevice 13 r is repeatedly disassembled and reassembled.

In this embodiment, as shown in FIGS. 16 and 17, brake shoe 41 consistsof a ring-shaped member divided into three segments in thecircumferential direction. A contact face 41 a is formed on the outerperipheral surface of each segment of brake shoe 41 for contacting thebrake face 51 a of drum body 43 during braking. Each contact face 41 ahas a cross sectional shape in the form of an isosceles trapezoidprojecting convexly in the radially outward direction so as to contactbrake face 51 a. The angle Î² of intersection of the two sides ofcontact face 41 a is equal to or greater than the intersect angle Î± ofbrake face 51 a. As shown in FIG. 18, sloping faces 41 e are formed atthe two end portions of the contact faces 41 a such that an acute angleÎ³ is formed with respect to a tangent line 81 at the location ofcontact of a sloping face 41 e with an arbitrary arc 80 on brake face 51a. By providing such sloping faces 41 e, grease delivered to the slopingfaces during rotation of the brake drum 40 can be supplied smoothly tothe brake face 51 a. Thus, grease depletion is not likely to occur atthe brake face 51 a. In the center of contact face 41 a is formed anannular housing recess 41 b in which a first spring member 53 ismounted. Housing recess 41 b is formed so as to be juxtaposed to firstgroove 54 a of grease filled recess 54 in drum body 43.

Three diametrically outwardly recessed rotation stop portions 41 cextending a predetermined length in the rotation direction is formed onthe inside peripheral surface of brake shoe 41. Three detainingprojections 34 f (FIGS. 6 and 8) formed on bracket body 34 of fasteningbracket 30 f fit within these rotation stop portions 41 c, thuspreventing rotation of the segmented brake shoe 41 relative to bracketbody 34. Of course, brake shoe 41 will rotate slightly due to playbetween detaining projections 34 f and rotation stop portions 41 c.

The first spring member 53 mounted in housing recess 41 b is an annularspring member formed by bending elastic wire material into a circle.Such a configuration makes it easy to bias each segment of brake shoe 41inwardly towards a position away from the brake drum 40 (i.e.,diametrically inward). A first end of the first spring member 53 has aprojecting portion 53 a that is bent to project diametrically outwardly.In this embodiment, projecting portion 53 a projects outwardlyapproximately 0.4 mm–2.0 mm from the inside peripheral portion. As aresult, when brake shoe 41 contacts the brake drum 40 during braking,the distal end of projecting portion 53 a tends to be situated withinfirst groove 54 a of grease filled recess 54. During brake release, whenthe brake shoe 41 comes away from the brake drum 40, projecting portion53 a tends to be situated diametrically inward from first groove 54 agroove. In this way, during braking (and possibly only during braking),projecting portion 53 a can rake out the grease packed into first groove54 a towards the brake face 51 a. The size of projecting portion 53 aalso ends to require no major change in the usual assembly machinery,assembly process, tools, or the like.

Brake actuating portions 33 f, 33 r are substantially identical inconstruction despite their difference in shape, so only the front brakeactuating portion 33 f will be described here. The front brake actuatingportion 33 f is rotatably disposed on fastening bracket 30, and it isused to push the segments of brake shoe 41 towards the brake drum 40. Asshown in FIGS. 8 and 19, the front brake actuating portion 33 f has anactuating arm 60 adapted to be mounted on the bracket body 34 offastening bracket 30 f so that actuating arm 60 rotates round the hubspindle 15 a; a cam member 61 that rotates in unison with the actuatingarm 60; a plurality of rollers 62 (e.g., six) disposed between andcontacting cam member 61 and brake shoe 41; and a roller case 63 forholding the rollers 62 spaced apart from each other in the rotationdirection.

Actuating arm 60 is fabricated from a metal plate. An inner mountingportion 64 is detachably mounted to the distal end of actuating arm 60for detaining the distal end of inner cable 16 f of brake cable 14 f.Actuating arm 60, which is actuated by means of inner cable 16 f viainner mounting portion 64, is linked to the brake lever 12 f mounted onthe handlebar portion 4 of the bicycle. The basal end of actuating arm60 is bent and has a mating hole 60 a (FIG. 8) for mating with theoutside peripheral face of cam portion 61. Actuating arm 60 rotatesbetween a brake released position (shown in FIG. 20) and a brakingposition (shown in FIG. 21) Actuating arm 60 is biased toward the brakereleased position by a second spring member 70 in the form of a torsioncoil spring. One end of spring member 70 is detained by bracket body 34,and the other end of spring member 70 is detained in a detaining hole 60b formed in the distal end of actuating arm 60. Second spring member 70is covered by cover member 35.

As shown in FIG. 19, a mounting slot 65 is formed on the distal end ofactuating arm 60 for detachably mounting the inner mounting portion 64.Mounting slot 65 proceeds up from the bottom of the distal end ofactuating arm 60, bends towards the rotational axis of the actuating arm60, and then bends diagonally downward. Slot 65 includes a constrictedportion 65 a that is disposed at the bent portion, wherein constrictedportion 65 a is narrower in width than other portions. In thisembodiment, constricted portion 65 a has a width d2 of 5.4 mm, and aback end/front end width d1 of 5.9 mm. An attachment/detachmentoperation portion 60 c used for attaching or detaching inner mountingportion 64 is formed at the bottom of the distal end of actuating arm60. Attachment/detachment operation portion 60 c also facilitatesrotation of actuating arm 60, of necessary, when attaching and detachinginner mounting portion 64 from actuating arm 60.

Inner mounting portion 64 has a plate-shaped arm body 66 formed bybending metal sheet material, a retaining portion 67 disposed at thebasal end of arm body 66 (the bottom end in FIG. 19), and a cabledetaining portion 68 screwed to the distal end of arm body 66. The basalend of arm body 66 is bent into a “U” configuration to form a bracketportion 66 a for supporting retaining portion 67. Retaining portion 67is detachably and rotatably mounted in mounting slot 65 of actuating arm60, and cable detaining portion 68 is provided for detaining inner cable16 f. An attachment/detachment operation portion 66 b that aligns withcable detaining portion 68 is formed at the distal end of arm body 66.Attachment/detachment operation portion 66 b extends away from cabledetaining portion 68 and then bends sideways. Inner cable 16 f thus maybe removed as a unit with inner mounting portion 64, and it is notnecessary to adjust the brake play every time the wheel is replaced.Also, since inner mounting portion 64 is a large member, it may beeasily removed with one hand.

Retaining portion 67 has a flanged retaining shaft 67 a fixed to bracketportion 66 a, a spring pin 67 b mounted on retaining shaft 67 a, and awasher 67 c disposed such that it contacts spring pin 67 b. Spring pin67 b has an axially extending slit formed in its outside periphery, andit may be formed by winding elastic sheet material. Spring pin 67 b hasan outside diameter greater than constricted portion 65 a of mountingslot 65, a width smaller than mounting slot 65 with the exception ofconstricted portion 65 a, and an inside diameter greater than theoutside diameter of retaining shaft 67. When spring pin 67 b is insertedinto the mounting slot 65 to mount the inner mounting portion 64 onactuating arm 60, spring pin 67 b inserts smoothly into the entrance ofmounting slot 65, is diametrically constricted as it passes through theconstricted portion 65 a of mounting slot 65, and then expands to itsoriginal shape once it has passed through the constricted portion 65 a.As a result, it will not return back through the constricted portion 65a during normal operation. However, when holding the twoattachment/detachment operation portions 60 c, 66 b, the retainingportion 67 moves easily out of the mounting slot, and the inner mountingportion 64 can be easily detached from the actuating arm 60.

Cam member 61 is nonrotatably fixed to actuating arm 60 so that itrotates in response to rotation of actuating arm 60. As shown in FIGS.8, 20 and 21, cam member 61 may be a thick-walled tubular memberfabricated of steel. A plurality of cam portions 61 c are formed on theouter peripheral face of cam member 61. Each cam portion 61 c has asloping cam face 61 a and a recessed portion 61 b. In this embodiment,the distance in the diametrical direction of each cam face 61 aincreases gradually in the clockwise direction in FIG. 20, and therecessed portions 61 b are recessed below adjacent pairs of sloping camfaces 61 a.

Roller abutting faces 41 d (FIG. 16) that project diametrically inwardlyare disposed at the inside peripheral surface at the two ends of eachsegment of brake shoe 41. Rollers 62 are mounted between the outsideperipheral surface of cam member 61 and the roller abutting face 41 d ofbrake shoe 41. Rollers 62 are used to push against brake shoe 41 inresponse to rotation of cam member 61. Rollers 62 are mounted in aroller case 63 in such a manner that they are spaced apart in acircumferential direction while being capable of movement in adiametrical direction in response to rotation of cam member 61. Morespecifically, a plurality of retaining projections 63 a (e.g., six) areformed in roller case 63. The retaining projections 63 a arecircumferentially spaced apart and project outwardly in the hub axialdirection for retaining the rollers 62. Roller case 63 is nonrotatablydetained to bracket body 34 by means of a retaining projection 63 b thatprojects axially further than the other retaining projections 63 a. Asshown in FIGS. 5, 6, and 8, a slot 34 g that is elongated in therotation direction is formed in bracket body 34 for mating with thisretaining projection 63 b. A third spring member 72 is mounted betweenretaining projection 63 b and bracket body 34 for biasing the rollercase 63 in the clockwise direction in FIG. 20. Thus, the rollers 62 aresubstantially fixed relative to bracket body 34. Grease is packed withinthe roller case 63 around the rollers 62 in the same manner as for brakeface 51 a so that rollers 62 can move smoothly in the diametricaldirection in response to rotation of cam member 61. The use of rollersalso helps to minimize evaporation of grease and the fluctuation inbraking performance due to a rise in brake temperature.

The operation of brake devices 13 f, 13 r will be described withreference to the front brake device 13 f described above. With the brakecables 14 f, 14 r set up, the inner cables 16 f, 16 r are under tension,and play between brake shoe 41 and brake drum 40 in the absence ofoperation of brake levers 12 f, 12 r may be adjusted by means of theouter detaining portion 22 mounted on brake lever s12 f, 12 r or theouter mounting portion s31 f, 31 r mounted on brake device 13 f, 13 r.In this state, squeezing the front brake lever 12 f causes the innercable 16 f to pull in opposition to the biasing force of the secondspring member 70, so that the actuating arm 60 rotates from the brakerelease position shown in FIG. 20 to the braking position shown in FIG.21.

When actuating arm 60 rotates to the braking position, cam member 61rotates integrally therewith, and the rollers 62 ride up over the slopedcam faces 61 a. As a result, rollers 62 are displaced diametricallyoutwardly and press the contact faces 41 a of brake shoe 41 against thebrake face 51 a of brake drum 40 in opposition to the biasing force ofthe first spring member 53. This initially produces a braking forceproportional to the pushing force on brake shoe 41. Since brake drum 40is rotating in the counterclockwise direction of FIG. 21 at this time,brake shoe 41 also turns slightly counterclockwise, and roller case 63rotates slightly in the same direction via rollers 62. This causesrollers 62 to be displaced further diametrically outwardly and producesan increased braking force. Since the brake face 51 a is recessed in atrapezoidal configuration and the contact face 41 a projects outwardlyin a trapezoidal configuration, the frictional contact force between thefriction faces increases through a wedging action. Since the contactarea is larger than it would be between flat peripheral surfaces, thefrictional force is larger and produces a high braking torque in a unitof compact size. On the other hand, the heat generated per unit ofsurface area is held to a lower level. Thus, high brake temperature isunlikely to occur, and a fluctuation in braking force due to a rise inbrake temperature can be reduced.

When the hand is released from front brake lever 12 f, actuating arm 60returns to the brake released position in accordance with the biasingforce of the second spring member 70. Since cam member 61 rotatesintegrally with actuating arm 60, rollers 62 ride down the sloped camfaces 61 a, and the brake shoe 41 moves diametrically inwardly inaccordance with the biasing force of the first spring member 53. At thistime, the roller case 63 rotates in the clockwise direction inaccordance with the biasing force of the third spring member 72, and thebraking force stops.

When assembling the brake drum 40, the drum body 43 and cooling disk 44forms are fabricated by a process such as die casting or forging, andthe forms are then finished to the desired dimensions by machiningprocesses. At that time, cooling disk 44 has a shape like that shown inFIG. 7( a), with caulk fastening portion 44 d having the form of acylinder. Cooling disk 44 then is press fit onto the outside peripheralsurface of drum body 43. After being press fit, caulk fastening portion44 d is bent diametrically inward towards the caulking face 51 d toeffect caulking of the cooling disk 44 to the drum body 43 using aroller or the like.

Then, two segments of the brake shoes 41 and the first spring member 53are assembled and mounted inside the drum body, and the remainingsegment of brake shoe 41 is attached so that the first spring member 53enters the housing recess 41 b. The interior may be packed with amplegrease at this time. When the mounting of brake shoe 41 is completed,the segments of brake shoe 41 are pushed against brake face 51 a, therollers 62 are mounted in the roller case 63, and both are inserteddiametrically inwardly of brake shoe 41. The interior may be furthercoated with ample grease at this time.

Then, the cam member 61 having the actuating arm 60 fastened thereto isinserted diametrically inwardly of rollers 62. Retaining member 36 isattached to tubular portion 34 d of bracket body 34, bracket body 34 isassembled to brake drum 40 so that retaining member 36 engages annularprotrusion 44 e on brake drum 40, and retaining member 37 is attached totubular portion 34 d of bracket body 34 from the outside to engageannular protrusion 44 e. The two kinds of retaining members 36, 37 thusprevent brake drum 40 from coming off. Finally, the third spring member72 is hooked between bracket body 34 and detaining projection 63 b ofroller case 63, and the cover member 35 is attached to complete theassembly procedure. The disassembly procedure is the reverse of theabove. Thus, fastening bracket 30 f and brake drum 40 may be removed asa unit from the frame, and then brake drum 40 may be removed fromfastening bracket 30 f by removing cover 35, prying retaining member 37from tubular portion 34 d of bracket body 34, and tilting bracket body34 to disengage retaining member 36 from the annular protrusion 44 e ofbrake drum 40.

When assembling the front wheel 6 having the brake device 13 f mountedthereon onto the front fork 3, the insert member 19 mounted on thedetaining portion 34 c of bracket body 34 of brake device 13 f is pushedinto bracket fastening portion 25 f, and the hub spindle 15 a of hub 6 ais mounted on front fork 3. The hexagonal cap nuts 45 are then installedon both ends of hub spindle 15 a and tightened to the appropriate levelof torque to complete mounting of the front wheel 6. Once the frontwheel 6 has been mounted, the inner mounting portion 64 is mounted onthe actuating arm 60 by inserting the spring pin 67 b into mounting slot65

The front wheel 6 may be removed by substantially reversing the aboveprocedure. However, when removing the inner mounting portion 64, theattachment/detachment operation portion 60 c is held with one hand, theattachment/detachment portion 66 b is held with the other hand, and theretaining portion 67 of the inner mounting portion 64 is withdrawn fromthe mounting slot 65. At this time, a small amount of force is needed toconstrict the diameter of the spring pin 67 b as it passes through theconstricted portion 65 a, but the part removes easily once past theconstricted portion. Since the inner mounting portion 64 is not a smallpart, unlike conventional ones, it is easily grasped and easy to attachand detach.

While the above is a description of various embodiments of inventivefeatures, further modifications may be employed without departing fromthe spirit and scope of the present invention. For example, a rollerbrake for braking the wheel hub was described, but the hub brake deviceis not limited thereto. The inventive features may be applied to a bandbrake or drum brake for braking the hub. The brake face 51 a and contactface 41 a in the described embodiment have a trapezoidal configuration,but the brake face 51 a and contact face 41 could be flat faces instead.While the insertion member 19 in the described embodiment was formedform a metal sheet, the insertion member may be easily molded from ahard synthetic resin. In the above embodiment, a cooling disc wasprovided with an annular protrusion formed thereon, but the outerperipheral surface of the drum main unit could have the annularprotrusion if no cooling disc is provided. Also, while the retainingmembers 36,37 were bent and fixed or based on elastic engagement, themethod for fixing the first detents is not limited to these options. Analternative method such as screwing can also could be used. A seconddetent was provided on the cover member 35 in the described embodiment,but the second detent may also be provided on the bracket main unit 34.

The method for crimping and/or caulking the cooling disk 44 is notlimited to that described in the preceding embodiment. For example, asshown in FIG. 22, a knurled portion 151 b formed on the outer peripheralsurface of a drum body 143 of a brake drum 140 may serve as the caulkingface. In this case, caulking is effected by compacting with a roller 180(shown by the broken line) towards the knurled portion 151 b from theouter peripheral surface of tubular portion 144 b. This method allowscaulking, spin prevention and fastening to be accomplished in a singleprocess. To prevent grease from flowing out, a sealing agent is appliedto the gap between the tubular portion 151 of drum body 143 and thetubular portion 144 b of cooling disk 144 to produce a sealed portion181. In this embodiment, the disk portion 144 c is not provided withcooling fins.

The size, shape, location or orientation of the various components maybe changed as desired. Components that are shown directly connected orcontacting each other may have intermediate structures disposed betweenthem. The functions of one element may be performed by two, and viceversa. The structures and functions of one embodiment may be adopted inanother embodiment. It is not necessary for all advantages to be presentin a particular embodiment at the same time. Every feature which isunique from the prior art, alone or in combination with other features,also should be considered a separate description of further inventionsby the applicant, including the structural and/or functional conceptsembodied by such feature(s). Thus, the scope of the invention should notbe limited by the specific structures disclosed or the apparent initialfocus or emphasis on a particular structure or feature.

1. A bicycle hub brake component for braking a hub of a wheel mounted ona bicycle frame, wherein the component comprises: a brake drum having adrum body adapted to rotate integrally with the hub, wherein the drumbody has a brake face on an inner peripheral surface thereof; a coolingdisk crimped to an outer peripheral surface of the drum body; whereinthe drum body has a crimping portion to which the cooling disk iscrimped; wherein the crimping portion of the drum body has a crimpingface that has a smaller diameter than another face of the drum body foraxially retaining the cooling disk in a first direction; and wherein thecooling disk has a free end portion that is bent radially inwardly toextend along the crimping face of the drum body and terminate in closeproximity to the crimping face of the drum body so that the bent freeend portion overlaps the crimping face of the drum body when viewedalong a direction of a rotational axis of the drum body.
 2. Thecomponent according to claim 1 wherein the cooling disk is press fit tothe drum body.
 3. The component according to claim 2 wherein the coolingdisk is caulked to the drum body.
 4. The component according to claim 1further comprising a brake shoe with a contact face that contacts thebrake face to apply a braking force to the brake drum.
 5. The componentaccording to claim 4 wherein the brake face has a cross-sectional shapein the form of a recessed trapezoidal configuration that constricts inwidth diametrically outward, and wherein the contact face has across-sectional shape in the form of a convex trapezoidal configurationthat constricts in width diametrically outward.
 6. The componentaccording to claim 4 further comprising a brake actuating component thatpresses the brake shoe against the brake face.
 7. The componentaccording to claim 6 further comprising a fastening bracket adapted tobe nonrotatably mounted to the bicycle frame for supporting the brakeactuating component.
 8. The component according to claim 7 wherein thebrake shoe is substantially nonrotatably mounted relative to thefastening bracket.
 9. The component according to claim 8 wherein thebrake actuating component is displaceably supported by the fasteningbracket.
 10. The component according to claim 9 wherein the brakeactuating component comprises: an actuating arm that is rotatable aroundan axis of the hub; a cam member that rotates integrally with theactuating arm, wherein the cam member has a contoured outer peripheralsurface; and a plurality of rollers disposed between the outerperipheral surface of the cam member and the brake shoe, wherein theplurality of rollers move diametrically outward in response to rotationof the cam member to move the brake shoe diametrically outward.
 11. Thecomponent according to claim 1 wherein the drum body has a detainingportion that inhibits axial movement of the cooling disk relative to thedrum body.
 12. The component according to claim 11 wherein the drum bodyhas a press fitting portion to which the cooling disk is press fit. 13.The component according to claim 12 wherein the detaining portion of thedrum body has a detaining face that tapers diametrically inward.
 14. Thecomponent according to claim 13 wherein the cooling disk has a detainingportion that engages the detaining portion of the drum body.
 15. Thecomponent according to claim 14 wherein the detaining portion of thecooling disk has a detaining face that tapers diametrically inward forengaging the detaining face of the drum body so that the detainingportion of the cooling disk overlaps the detaining portion of the drumbody when viewed along the direction of the rotational axis of the drumbody.
 16. The component according to claim 15 wherein the crimping faceof the drum body tapers diametrically inward.
 17. The componentaccording to claim 16 further comprising a knurled portion formed on oneof the drum body and the cooling disk for engaging the other one of thedrum body and the cooling disk.
 18. The component according to claim 1wherein the cooling disk comprises: a tubular portion; a disk portionextending diametrically outward from the tubular portion; and whereinthe cooling disk is crimped to the drum body by bending a first end ofthe tubular portion diametrically inward toward the crimping face of thedrum body.
 19. The component according to claim 18 wherein the crimpingface of the drum body tapers diametrically inward, and wherein thecrimping face of the drum body engages the first end of the tubularportion of the cooling disk.
 20. The component according to claim 19wherein the drum body has a detaining portion on a second end thereof,wherein the detaining portion of the drum body has a detaining face thattapers diametrically inward, and wherein a second end of the tubularportion of the cooling disk has a detaining portion with a detainingface that tapers diametrically inward for engaging the detaining face ofthe drum body.
 21. The component according to claim 20 wherein the drumbody has a press fitting portion to which the cooling disk is press fit,wherein the press fitting portion is disposed between the detaining faceof the drum body and the crimping face of the drum body.
 22. Thecomponent according to claim 21 wherein the disk portion of the coolingdisk has a plurality of cooling fins spaced apart in a circumferentialdirection.
 23. The component according to claim 1 further comprising aplurality of circumferentially spaced recessed portions formed around anouter peripheral surface thereof the drum body.
 24. The componentaccording to claim 23 wherein the cooling disk is crimped to theplurality of circumferentially spaced recessed portions.
 25. Thecomponent according to claim 1 wherein the drum body has a detainingportion with a detaining face that has a smaller diameter than anotherface of the drum body to inhibit axial movement of the cooling diskrelative to the drum body in a second direction opposite the firstdirection.
 26. The component according to claim 25 wherein the drum bodyhas a press fitting portion to which the cooling disk is press fit. 27.The component according to claim 25 wherein the detaining face of thedrum body tapers diametrically inward.
 28. The component according toclaim 27 wherein the cooling disk has a diametrically inward extendingdetaining portion that engages the diametrically inward tapereddetaining face of the drum body.
 29. The component according to claim 28wherein the detaining portion of the cooling disk has a detaining facethat tapers diametrically inward for engaging the diametrically inwardtapered detaining face of the drum body.
 30. The component according toclaim 29 wherein the crimping face of the drum body tapers diametricallyinward.
 31. The component according to claim 1 wherein the detainingportion of the drum body is laterally opposite the crimping portion ofthe drum body.